The term silicone resin has been applied both to and misapplied to a variety of materials over time. Silicone resins as used herein refer to a series of products which include at least two silicone backbones that are joined by a “crosslinking group”. The number of crosslinking groups that are present as a percentage of the total molecular weight will determine the properties of the resulting polymer.
If there are no crosslinking groups; the polymer can freely rotate and consequently is an oily liquid. If a few crosslinking groups are introduced, the ability to rotate is slightly restricted and the oily material becomes “rubbery”. The rubbery material should be referred to as an elastomer. The properties are morel like a rubber band than plastic. As the percentage of crosslinking increases still the molecule becomes rigid. This class of compounds are resins. If you hit the film with a hammer and it shatters it is a resin, if it bounces it is an elastomer and if it squirts out is a silicone fluid.
The difficulty in determining if a product is a fluid an elastomer or resin occurs for products that lie between the classifications. Specifically, when does an elastomer become a resin? While this exact point is of academic interest it does not have any practical significance to the present invention.
There are a number of classes of resin compounds differing in the nature of the crosslinker. One class is the so called “Q resins”.

The oxygen that needs another bond connects to another polymer as shown:

The crosslinking group is —O—. This type of resin is disclosed in U.S. Pat. No. 6,139,823, incorporated herein by reference. This type of material has a group, the so called “Q” group in which a Si has four oxygen atoms attached. In the above case it is the group that is within the “a” subscript. This type of resin is very powdery and is rarely used without a plasticizer. This class of compounds can also dry the skin.
The next class of resin contain alkyl connecting groups.

In the case where n=1 acetylene is used as a crosslinking reactant. It is reacted with a silanic hydrogen polymer. As n is increased the reactant is an alpha omega divinyl compound.


The reaction is called hydrosilylation and provides the linking groups between the molecules. The reaction is generally run in solvent like cyclomethicone (D4 or D5 or hexamethyl disiloxane) or in volatile organic like isododecane. A catalyst generally a platinum one is used to effect the reaction. Chloroplatinic acid or Karnsteadt catalyst are preferred. The resulting material is a viscous liquid that when the solvent evaporates provides a film.
The present invention makes use of novel crosslinking reagents that provide groups that significantly alter the solubility of the resin. This is done by introducing fatty ester linkages, water soluble groups linked with fatty esters and glyceryl esters. Not only does the solubility change, the ability to formulate solid products free from syneresis also occurs. Another unexpected benefit is that the ester moiety provides improved biodegradation of the resin making the resin “more green” and improving consumer acceptability. None of these advantageous are present in the compounds known heretofore.